Corrosivity potential of Hong Kong drinking water

Abstract

A survey was carried out to determine the spatial and seasonal variations of pH and the calcium carbonate saturation index of Langelier (SI) in Hong Kong drinking water at the tap. The results obtained show that the SI values of all samples was negative, thus signifying serious potential corrosivity problems. Laboratory tests on adjustment of the SI value by chemical modification proved that the adjusted SI values were not stable and dropped sharply within a few days of storage. The findings indicate that the water quality changes significantly within the distribution system and the water inside service within buildings. The implications with regard to water treatment and introduction of different types of pipe materials are discussed. | A survey was carried out to determine the spatial and seasonal variations of pH and the calcium carbonate saturation index of Langelier (SI) in Hong Kong drinking water at the tap. The results obtained show that the SI values of all samples was negative, thus signifying serious potential corrosivity problems. Laboratory tests on adjustment of the SI value by chemical modification proved that the adjusted SI values were not stable and dropped sharply within a few days of storage. The findings indicate that the water quality changes significantly within the distribution system and the water inside service within buildings. The implications with regard to water treatment and introduction of different types of pipe materials are discussed.